Digital simulation of EHV systems under secondary arcing conditions associated with single-pole autoreclosure

The effectiveness of single-pole autoreclosure (SPAR) in maintaining power-system stability is largely determined by the speed with which secondary arc extinction, and hence autoreclosure, can be achieved. Realistic simulation techniques are of obvious importance in relation to the design of systems employing SPAR and, in the paper, digital methods are developed to enable the faulted response of EHV feeders, subjected to secondary arcing phenomena, to be more realistically simulated than has hitherto been possible. The new techniques are also of importance in relation to programmable based protection test equipment. Based upon experimental data, methods of modelling the nonlinear behaviour of the earth-fault arc path, in both conducting and extinction states, are described; together with the techniques developed for incorporating such models into practical EHV system interconnections. The paper concludes by illustrating and discussing the results of a computational study relating to a typical short 500 kV feeder employing SPAR.